I have used Turbotax in the past and I've never been asked to upgrade on the basis of my education background until now. Can anyone explain?

What?   Do you mean you had to upgrade in order to get the student loan interest deduction?   You cannot get that deduction using the Free Edition---you do have to upgrade to Deluxe.   Is that what you are calling an upgrade on the basis of your education background?   Or do you mean something else?

Do you qualify to use Free File instead?

https://ttlc.intuit.com/questions/2586254-how-do-i-clear-and-start-overIf you qualify to use it, there is another full-featured free version of the software:

Try Free File: 

You qualify if your income was $39,000 or less, or $72,000 or less if active duty military, or if you qualify for Earned Income Credit

https://ttlc.intuit.com/questions/1900583-what-is-turbotax-free-file-program

• https://ttlc.intuit.com/questions/2026912-how-do-i-switch-to-turbotax-free-file-program

Note:  If you do not qualify to use Free File then you will have to upgrade to Deluxe or higher in the paid versions of the software.   

 Online Deluxe $40  State software $40

Or—-Use this IRS site for other ways to file for free

https://apps.irs.gov/app/freeFile/